Roll grooving apparatus

ABSTRACT

A roll grooving apparatus has a back-up roller, a grooving roller positioned vertically below the back-up roller, and a hydraulic jack positioned directly vertically below the grooving roller, with the hydraulic jack exerting an upward force to push the grooving roller towards the back-up roller to form a circumferential groove in a pipe segment that is positioned between the rollers.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a roll grooving apparatus, and inparticular, to tools that create circumferential grooves in pipes toallow the pipes to be connected together end to end using mechanicalcouplings.

2. Description of the Prior Art

Mechanical couplings are used to couple pipes and to one another andeffect a fluid tight joint. Couplings may comprise a pair of pipesegments that are joined to one another end to end by fasteners tocircumferentially surround the ends of the pipe segments. To effect asubstantially rigid joint (i.e., a joint which resists relative rotationof the pipe segments about their longitudinal axes, resists axial motionof the pipe segments relatively to one another due to internal pressure,and resist angular deflection of the pipe segments relatively to oneanother), it is advantageous to position circumferentially extendinggrooves around each pipe. The grooves are positioned in spaced relationto the ends of the pipe segments and are sized to receive arcuatelyshaped keys extending from each pipe segment. Engagement of the keyswith grooves helps the joint formed by the coupling to stay rigid.

Assembly of piping networks using mechanical pipe couplings may requirethat pipe stock be cut to a desired length, the cut pipe segments bereamed to remove burrs and sharp edges, and grooves be formed in bothends of each cut pipe segment. The cut, reamed and grooved pipe segmentsmay then be joined to one another using the couplings described above.

Forming circumferential grooves in pipes made of malleable materialssuch as plastics, copper, steel and aluminum can be accomplished by coldworking the material beyond its yield stress, thereby causing apermanent deformation in the material. Existing techniques for formingcircumferential grooves in metal and plastic pipes entail sandwichingthe pipe sidewall between the circumferences of two adjacent rotatablerollers. One roller, known as the back-up roller, is positioned on theinside of the pipe, and the other, known as the grooving roller, ispositioned on the outside. The back-up roller has a concave die aroundits outer circumference and the grooving roller has a raised groovingsurface around its outer circumference. With the pipe sidewall betweenthem, the rollers are rotated in opposite directions and are forcedtoward one another so that they apply pressure to the sidewall. The dieand the grooving surface traverse the pipe circumference and cooperateto cold work the sidewall and produce a circumferential groove of thedesired size and shape. The rollers may move relatively to the pipe orthe pipe may rotate about its longitudinal axis and move relatively tostationary rollers.

The method using a grooving roller and a back-up roller is effective atforming grooves in pipe walls while maintaining the roundness of thepipe because the pipe sidewall is mutually supported between the rollersand is never subjected to compressive point loads which would tend tocollapse the pipe or force it out of round. Both rollers cooperate towork the material comprising the pipe, the grooving roller forming thegroove and the back-up roller acting as a die to control the flow ofmaterial during cold working and precisely define the groove shape.

Unfortunately, many of the conventional roll grooving apparatus sufferfrom one of many drawbacks. For example, many of these conventional rollgrooving apparatus are bulky and not convenient to use. In this regard,some of these conventional roll grooving apparatus are large and heavy,are difficult to install, include many components, and occupy a lot ofspace during use. As another example, in some conventional roll groovingapparatus, the construction and interaction of the grooving andback-rollers restrict the use of the roll grooving apparatus to pipeshaving certain diameters.

SUMMARY OF THE DISCLOSURE

It is an object of the present invention to provide a roll groovingapparatus which addresses the drawbacks set forth above.

In order to accomplish the objects of the present invention, the presentinvention provides a roll grooving apparatus having a back-up roller, agrooving roller positioned vertically below the back-up roller, and ahydraulic jack positioned directly vertically below the grooving roller,with the hydraulic jack exerting an upward force to push the groovingroller towards the back-up roller to form a circumferential groove in apipe segment that is positioned between the rollers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a roll grooving apparatus according tothe present invention mounted on a power drive unit.

FIG. 2 is an exploded perspective view of a portion of the roll groovingapparatus of FIG. 1.

FIG. 3 is a side plan view of the roll grooving apparatus of FIG. 1shown without the side plate.

FIG. 4 is a front plan view of the roll grooving apparatus of FIG. 1.

FIG. 5 is a top plan view of the roll grooving apparatus of FIG. 1.

FIG. 6 is a side plan view of the roll grooving apparatus of FIG. 1shown with the side plate.

FIG. 7 is an exploded perspective view of a bearing housing assembly forthe back-up roller of the roll grooving apparatus of FIG. 1.

FIG. 8 is an exploded perspective view of a secondary housing for thegrooving roller of the roll grooving apparatus of FIG. 1.

FIG. 9 is a top plan view of a hydraulic jack that can be used with theroll grooving apparatus of FIG. 1.

FIG. 10 is a perspective view of the roll grooving apparatus of FIG. 1shown with the power drive unit and a carriage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description is of the best presently contemplatedmodes of carrying out the invention. This description is not to be takenin a limiting sense, but is made merely for the purpose of illustratinggeneral principles of embodiments of the invention. The scope of theinvention is best defined by the appended claims.

FIG. 1 shows a roll grooving apparatus 10 according to the presentinvention being removably mounted on a power drive unit 12 of a pipemachine for power operation. Referring also to FIGS. 2-6, the apparatus10 has a housing 14 on which are mounted a back-up roller 16 and agrooving roller 18, positioned adjacent to the back-up roller 16. Theback-up roller 16 is rotatable about an axis 20, and the grooving roller18 is rotatable about an axis 22. Both axes of rotation 20 and 22 arepreferably substantially parallel to one another and to the longitudinalaxis (which is the same as the axis 20) of a pipe segment 26, shown inphantom line in FIG. 1 with its sidewall 28 positioned between therollers 16 and 18 for formation of a circumferential groove. As bestshown in FIG. 3, the grooving roller 18 is positioned directly below theback-up roller 16 at a six o'clock position with respect to the back-uproller 16.

The housing 14 has a generally inverted S-shape, with a horizontal topplate 32. A vertical front plate 34 extends vertically downwardly fromthe front edge of the top plate 32. The front plate 34 has a recessedbottom vertical portion 36 that extends vertically from the rear surfaceof the front plate 34 adjacent the bottom of the front plate 34. Ahorizontal base plate 38 extends horizontally forward from the bottom ofthe vertical portion 36. The portion 36 is recessed from the front plate34 to provide clearance for the hydraulic jack 100 (described below) tobe positioned in a manner such that the piston 104 can be in turnpositioned so that the force of the grooving roller 18 is directed tomaximize the energy through the sidewall 28 into the surface 134 of theback-up roller 16.

The back-up roller 16 is attached to a drive shaft 40 housed in abearing housing assembly 42 that is rotatably mounted to the front plate34 of the housing 14 adjacent the top plate 32. Referring also to FIG.7, the bearing housing assembly 42 has a bearing housing 44 with twobearings 46 positioned at opposite ends of the bearing housing 44. Asnap ring 48 is positioned adjacent each bearing 46, with a shaft spacer50 positioned between the rear snap ring 48 and two nuts 52. The driveshaft 40 extends through the bearings 46, the bearing housing 44, thesnap rings 48 and the spacer 50, and the nuts 52 are screwed on to thethreaded end of the drive shaft 40. The drive shaft 40 directly turnsthe back-up roller 16 about axis 20. As best shown in FIG. 2, the driveshaft 40 extends outwardly from housing 14 and is engageable with achuck 56 of the power drive unit 12. Chuck 56 has jaws 58 that aremovable into and out of engagement with drive shaft 40 by rotating achuck ring 60. The apparatus 40 is mounted on the power drive unit 12for power operation by rotating the chuck ring 60 to open the jaws 58(see FIG. 2), engaging the drive shaft 40 within the jaws 58, and thenturning the chuck ring 60 to lock the jaws 58 onto the drive shaft 40.An electric motor (not shown) in the power drive unit 12 rotates thedrive shaft 40, thereby rotating the back-up roller 16. A pair ofanti-torque support bars 158 extend from the housing 14 and are adaptedto be rested on top of corresponding stationary carriage rails 160extending from the power drive unit 12 to prevent the housing 14 fromturning when torque is applied to the drive shaft 40.

The grooving roller 18 is rotatably mounted in a secondary housing 70that is mounted to the housing 14. Referring to FIGS. 1, 3 and 8, thesecondary housing 70 has a U-shaped mount 72 whose bottom surface issecured to a platform 74. The U-shaped mount 72 defines an interiorspace 76 that receives the grooving roller 18 and two bearings 78positioned on either side of the grooving roller 18. A shaft 80 extendsthrough openings (e.g., 82) in the walls of the mount 72, the bearings78 and the grooving roller 18. One of the walls (see 84) of the mount 72is positioned adjacent to a portion of the front plate 34 at a locationbelow the back-up roller 16. A block 86 is secured to the rear of thefront plate 34 at the location opposite to the wall 84, and carries athreaded bolt 88. Another threaded bolt 90 extends from the rear of therecessed vertical portion 36, and the bolts 88, 90 are used to secureopposite ends of a spring 92. The spring 92 forcibly retracts thegrooving roller 18 from the groove which was formed into the sidewall 28of the pipe segment 26, and also forces the piston 104 of the hydraulicjack 100 down to its bottom starting position (after the release valve106 has been opened). By performing these two functions, the spring 92allows the pipe segment 26 to be removed so that a new segment of pipecan be placed between the rollers 16 and 18.

The platform 74 also serves as a shield for the hydraulic jack 100 fromdebris and pipe scale dropping from the grooving roller 18.

A hydraulic jack 100 is positioned on the base plate 38, and functionsto raise and lower the secondary housing 70 and the grooving roller 18carried thereon. The hydraulic jack 100 can be embodied in the form of ahydraulic bottle jack, an example being the SIDEWINDER JACKS™ being soldby SPX Corporation under its POWERTEAM™ trademark. Referring to FIGS. 3,4 and 9, the hydraulic jack 100 has a body 102 with a piston 104oriented vertically. A fluid reservoir (not shown) is contained insidethe body 102. The piston 104 is adapted to push the platform 74upwardly. A release valve 106 is positioned at one side of the body 102,and a plunger 108 extends from the body 102 at a location that is aboutninety degrees from the location of the release valve 106. A socket 112is provided at the end of the plunger 108, and a removable handle 110 iscoupled to the socket 112. The hydraulic jack 100 may be operated bypivoting the handle 110 left and right in a plane which is parallel tothe ground, causing the piston 104 to elevate, thereby pushing theplatform 74 and the secondary housing 70 upwardly. To lower thesecondary housing 70, the user merely opens the release valve 106.

A depth adjustment mechanism is provided to control or restrict theextent to which the hydraulic jack 100 can raise the platform 74. Thedepth adjustment mechanism has a threaded bar 120 which extendsvertically from the base plate 38 and through the platform 74. Aplurality (e.g., two) nuts 122 are threadably adjusted along the lengthof the bar 120 at the top surface of the platform 74 to control theheight to which the platform 74 can be raised by the hydraulic jack 100.

The roll grooving apparatus 10 can be operated in the following manner.A pipe segment 26 is positioned so that its sidewall 28 is locatedbetween the rollers 16, 18, and with the end of the pipe segment 26resting on a shoulder 118 adjacent the back-up roller 16 along the frontsurface of the front plate 34. The grooving roller 18 is raised towardthe back-up roller 16 by operating the hydraulic jack 100 until bothrollers 16, 18 engage opposite surfaces of the sidewall 28. The powerdrive unit 12 is switched on and turns the drive shaft 40, which in turnrotates the back-up roller 16 about its axis 20, the back-up roller 16being engaged with the inner surface of the sidewall 28. Frictionbetween the back-up roller 16 and inner surface causes the pipe segment26 to rotate about its longitudinal axis in response to the rotation ofthe back-up roller 16. Preferably, the back-up roller 16 has knurledcircumferential surfaces 130 (see FIG. 7) which provide increasedtraction between the back-up roller 16 and the pipe segment 26 to ensurethat the pipe segment 26 rotates. When the pipe segment 26 rotates,friction between it and the grooving roller 18 causes the groovingroller 18 to rotate about its rotation axis 22, the grooving roller 18thereby traversing the circumference of pipe segment 26. The groovingroller 18 has a raised circumferential surface 132 (see FIG. 8) thatengages the outer surface of the sidewall 28 and forms a groove in thesidewall 28 by cold-working the sidewall 28. The hydraulic jack 100 ispumped incrementally as the pipe segment 26 rotates to apply greaterpressure between the rollers 16, 18 and the sidewall surfaces with eachrevolution of the pipe segment 26 so as to gradually form the groove tothe desired depth and shape. The depth is determined substantially bythe height of raised surface 132 and the degree to which it is pressedinto the outer surface of sidewall 28. The shape of the groove isdetermined by the shape of the raised surface 132 and by the shape ofthe opposing surface 134 of the back-up roller 16 (see FIG. 7), whichacts as a die to control the flow of material comprising the sidewall28.

The housing 14 further includes two angled side plates 150, each sideplate 150 being secured to opposite sides of the roll grooving apparatus10. Referring to FIGS. 4 and 6, each side plate 150 has a top edge 152that is welded to the top plate 32, and a bottom edge 154 that is weldedto the base plate 38. A threaded opening 156 is provided for receivingopposing support bars 158 that extend transversely to the orientation ofthe roll grooving apparatus 10. Couplers 190 extend from each side plate150, and each support bar 158 is adapted to be threadably connected to acorresponding coupler 190. Each coupler 190 can have an inspection hole192 so that the user can see if the support bar 158 has been completelythreaded into the coupler 190. The support bars 158 are adapted to berested on top of corresponding carriage rails 160 (see FIG. 1) thatextend from the power drive unit 12.

Referring now to FIG. 10, a carriage 170 can be mounted to the frontends of the carriage rails 160. A pipe cutter 172 and a pipe reamer 174(both of which are well-known in the art) can be attached to thecarriage 170. As best shown in FIG. 10, the roll grooving apparatus 10can be conveniently fitted into the space defined by the carriage 170and the carriage rails 160 without the need to remove the carriage 170.This is to be contrasted with other conventional roll groovingapparatus, where the carriage (such as 170) must first be removed beforethe roll grooving apparatus can be installed on the power drive unit 12.

The overall construction of the roll grooving apparatus 10 and theorientation of its various components allow for the provision of acompact roll grooving apparatus 10 that occupies minimal space and whichis convenient to use.

First, by positioning the hydraulic jack 100 directly below (i.e., atthe six o'clock position) the grooving roller 18, pipe segments havingdifferent sizes can be grooved. Exerting an upward force on the groovingroller 18 maintains the bottom planar alignment of pipe segments withdifferent diameters because the elevation (i.e., the floor or theground) is constant or uniform. Therefore, pipe stands to support longerpipe segments do not require adjustment up or down when grooving pipesegments of different diameters. In contrast, some conventional rollgrooving apparatus that push the grooving roller downwardly (i.e., froma twelve o'clock position) require that pipe stand be adjusted up ordown when grooving pipe segments of different diameters. This is becausethese conventional roll grooving apparatus which push a grooving rollerdown from the twelve o'clock position are limited to the space betweenthe back-up roller and the ground.

Second, all of the required hydraulics (including the hydraulic fluidreservoir) are located inside the hydraulic jack 100. Therefore, it isnot necessary to provide an auxiliary hand pump and hose located in aseparate location, thereby minimizing components and making thehydraulic system more compact. The location of the handle 110 does notprovide clearance problems because it is neatly positioned below therollers 16, 18 and does not protrude clumsily. The handle 110 utilizes aleft-right pumping axis which does not interfere with any of the othercomponents of the roll grooving apparatus.

Third, the roll grooving apparatus 10 can be quickly and convenientlyinstalled for use. As shown in FIGS. 1 and 10, the housing 14 can besimply lowered into place with the support bars 158 rested on top ofcorresponding carriage rails 160 that extend from the power drive unit12, and the roll grooving apparatus 10 is ready for use. There is noneed to remove any of the other components of the power drive unit 12 orthe roll grooving apparatus 10.

Fourth, the overall construction of the roll grooving apparatus 10 iscompact, thereby making it portable and easy to move around, and tohandle.

Fifth, the carriage frame 170 can serve as a support surface whenplacing or removing a pipe segment 26 between the rollers 16, 18. Forexample, referring to FIG. 10, the pipe segment 26 can be temporarilyrested on the frame of the carriage 170 before fitting it against theshoulder 118 between the rollers 16, 18. In addition, when the groovedpipe segment 26 is removed after grooving, the pipe segment 26 can beremoved from the rollers 16, 18, and temporarily rested on the frame ofthe carriage 170 so that the user can inspect the groove for properdepth. If the groove is acceptable, the user can remove the pipe segment26. If the groove is not acceptable, the user can conveniently place thepipe segment 26 back between the rollers 16, 18 for further grooving.This feature further illustrates the convenience afforded by theconstruction of the roll grooving apparatus 10.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The accompanying claimsare intended to cover such modifications as would fall within the truescope and spirit of the present invention.

1-11. (canceled)
 12. A roll grooving apparatus and power drive unit incombination, the combination comprising: a back-up roller and a groovingroller of the roll grooving apparatus, the back-up roller and thegrooving roller positioned in mutual proximity with axes thereofarranged in mutually parallel positions; one or the back-up roller andthe grooving roller engaged with the power drive unit; and the other ofthe back-up roller and the grooving roller supported by a movableplatform of the roll grooving apparatus, the movable platform in contactwith a jacking device of the roll grooving apparatus: a pair oftransverse support bars of the roll grooving apparatus resting oncarriage rails of the power drive unit in supporting the weight of theroll grooving apparatus; the jacking device extendable and retractableover a range of motion, with extendable motion thereof drawing theback-up roller and grooving roller into mutually intimate proximity, andwith retractable motion of the jacking device drawing the back-up rollerand the grooving roller into mutually distant proximity.